Valve grinder dressing tool



April 30, 1935. 4r. o. ALBERTsoN 1,999,435

l VALVE GRINDER DRESSING` TOOL Filed Feb. 19, 1934 5 sheets-sheet 1 pr 3U, l93 F. o. ALBERTSN 1,999,435

VALVE GRINDER DRESSING TOOL prill 30, 1935.. l F. o. ALBERTSQN y L999y435 VALVE GRINDER DRESSING TooL Filed Feb. 19, 1934 3 Sheets-Sheet 3 @gig-.6.

atented Apr. 3Q, 1935 UNITED STATES F F i Y 1,999,435 VALVE GRINDER DRESSING TOGL corporation of Iowa Application February 19, 1934, Serial No. 711,847

8 Claims.

The present invention relates to valve grinder dressing tools, and is particularly concerned with the provision of an improved dressing tool for use with the valve seat grinder described and covered by my co-pending application, Serial No.

711,848, filed February 19, 1934.

The present dressing tool may, however, be used with all types of grinding stones, provided the tool holder is of suitable size to be supported 10 upon the dressing tool pilot.

' One of the diiliculties encountered with the dressing tools of the prior art is that the cuttings become lodged on the diamond supporting plunger and soon wear away the plunger or its guide in such manner that the dressing tool is no longer accurate. Another difculty lies in the 'fact that wear takes place on the supporting threaded member for the diamond and the lost motion which results from these worn parts also aects the accuracy of the dressing tool.

One of the objects of the invention is the provision of an improved grinding stone dressing tool which has its diamond supporting plunger suitably protected from they grindings, etc., so that the plunger and its guide will not be worn and may be used for long periods of time without impairing their accuracy.

Another object of the invention is the provision of an improved dressing tool of the class described in which the lost motion due to the -wear or loose fit of the threaded diamond-supporting member is always taken up by means of a spring contrivance so that increased accuracy will result.

Another object of the invention is the provision of an improved actuating mechanism for the diamond-supporting plunger, by means of which the diamond may be moved with greater uniformity across the surface of the stone in the dressing operation and by means of which the sticking andY corresponding jerky movement of the plunger is eliminated.

Another object of the invention is the provision of an improved dressing tool which is simple in construction, sturdy, and capable of mass production, so that the invention may be brought within the means of a vast number of users who may practice the grinding and dressing methods and utilize the tool as described herein.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, in which sirnilar characters of reference indicate similar parts throughout the several views.

Referring to the drawings, of which there are three sheets:

v Fig. 1 is a side elevational View of the dressing tool, tool holder, stone, and motor driver during the operation of dressing of the stone;

Fig. 2 is a fragmentary sectional view of the lower end of the motor driver, showing the resiliently supported drive shaft;

Fig. 3 is a rear elevational View of the dressing tool with a tool holder and stone in place;

Fig. 4 is a top plan View of the dressing tool without the tool holder and stone;

Fig. 5 is a front elevational View of the dressing tool with the tool holder and stone, the tool holder and parts of the dressing tool being shown in section in order to show the details of the mechanism;

Fig. 6 is a fragmentary sectional View of a part of the dressing tool, taken on the plane of the line 6 6 of Fig. 5, looking in the direction or" the arrows, and showing the details of construction of the plunger and diamond securing screw;

Fig. Z is a fragmentary front elevational view of the dressing tool in partial section, showing the details of structure of the dressing tool, pilot, and adjustable support for the grinding stone;

Fig. 8 is a fragmentary sectional View taken on the plane of the line of Fig. 4, looking in the direction of the arrows, showing certain details of construction of the operating handle.

The complete dressing tool assembly preferably comprises the motor driver Zi), the tool holder 2i, the dressing tool 22, and the dressing tool pilot 23 (Fig. 5). The motor driver 253 preferably consists of a series wound coinmutator motor having suitable speed increasing gearing and provided with an axially extending drive shaft terminating in the driving knuckle 2li. The details of construction of the drive shaft of the motor driver are shown in Fig. 2, where the drive shaft 25 is rotatably and slidably mounted in the lower end of the motor driver by means of anti-friction bearings 2e, 21.

All of the details of the motor driver may be substantially as described in my co-pending application, Serial No. 711,848, iiled February 19, 1934, for Valve seat grinding machines, and therefore it is not necessary to describe all of these details except to point out that the shaft 25 is supported for axial movement as well as rotation on account of the movement of the lower bearing 2l in its socket, and the shaft is urged to outward position by a. spring washer Z3 which engages the lower bearing and also engages the bearing housing to urge the shaft pered steel. be used together, the tool holder rotating on base of `the counterbore 53. :the adjacent flat surface 55 of the dressing tool body and .theglat surface 53A of theplunger-supdownward. The weight of the motor is thus resiliently supported by means ci the shaft 25 and spring washer E8 when the motor is permitted to rest on the dressing tool with its shaft end in the socket of the tool holder and the grinding stone is protected from shocks to which it might otherwise be subjected.

Thedriving knuckle 2d is provided with a lower noncircular or hexagonal end '2Q which is adapted to engage in a noncircular socket te in the upper end of the tool holder 2E so as to drive the tool holder with the drive shaft 25.

The tool holder 2| is similarin construction to that described in my co-pendingapplication for Valve seat grinding machines, mentioned above. It comprises a metal supporting sleeve 3l, upon which is mounted a handle o r housing 32 oi insulating material. At its lower end the supporting sleeve 3i has a threaded extension 33,v

upon which the hub 35i of the grinding stone 35 is mounted.

The sleeve 3l is lined with a hardened steel bearingsleeve 3S, which may be made in two separate parts, if desired, and the pilot 23 has an upper cylindrical part, also made of hard ltern- These two parts are adapted to the pilot without the wear oi these parts by means of the cuttings, because both of the parts are too hard to take up or support the cuttings, and all that is necessary is to keep the pilot and the complementary sleeve suitably lubricated to prevent the wear or" these parts by long use.

At its upper end the lsupporting sleeve 3i supports an end plug 3l which has a threaded bore 33 for receiving the threaded member Sii, having the hexagonal aperture Sii. The plug 3i lhas an annularv seat lit, upon which is seated a spring washers! of tempered resilient steel and having a plurality of radially extending ribs 42. The spring washer .tl is clamped between the shoulder B and the threaded member 39, and the hexagonalend 2% of the driving-knuckle rests upon the spring washer lil.

All of the parts so far described maybe substantially as disclosed in the co-pending application for Valve seat grinders, referred to above,

as the same tool holder, motor driverand grind- `tionwi ofthe webhas an arcuateslot t3, through --which Ypasses a clarnpingbolt iL'having a transverse vpin (d3 for engagement with the fingers.

"The upwardly extending web it is also provided 4with a transversely ext-ending bore fig for rotatablysupporting a screw bolt 53, which serves as .a ntrunnion for the pivoted plunger supporting member 5l.

Screw bolt' passes through the bore es and -is threaded into a threaded bore 52 in the plunger-supporting member 5l. The web or ibody M of the dressing tool is provided with a counterbore 53 and a helical spring 55. is compressedbetween the head of the bolt-,59 and the Spring 56 draws porting arm into engagement `with eachother and tendstohold the plunger-supporting member YEil in any adjusted position.

The screw bolt il is threaded into a bore 56 in the plunger-supporting member 5I and has an annular shoulder iii which engages the rear side oi the web or body fifi to clamp the body of the dressing tool and the plunger-supporting member 5i together.

A suitable washer 58 may be interposed between the shoulder 5l `and the body 44, if desired. The arcuate portion 55: ofV the upwardly extending web lili is provided with a cylindrical surface 59, the axis of generation of which lies in the axis of the screw bolt 5G, and this cylindrical surface is provided with indicia 66 (Fig. vll) indicating the angle at which the plunger of the dressing tool may be set.

The plunger-supporting member 5l is provided with a longitudinally extending bore Si, serving as a guide-forthe plunger 62. The bore 6I and plunger -52 are preferably cylindrical in shape and are accurately and closely iitted to each other so that the plunger moves upward and downward through the bore l with afminimum of play or tolerance.

In the devices of the prior art, the frequently `got into the guideV of the and soon the guide and plunger were both so worn that they could no longer perform their functions accurately.

In the present invention the borel preferably leads to counterbores G3 at each end, and the counterbores $3 are provided with suitableoil seals, each of .which may be identical in construction. For exainplefthe oil seal may consist of a leather washer having a cylindrical portion T64 and an outwardly extending vflange 65. The iiange 65 is conned in place by means of an inwardly extending flange 66 on a channeled annular member i'i. A helical garter spring 58 extends about the cylindrical ange 84 of the leather and urges it into engagement with the plunger ,62.

A metal washer plate 69 is located outside of the garter spring and is held in place bythe inwardly extending iiange l@ oi the channeled membert'l. The channeled member 6'! may be a close frictional it in the counterbore 63.

It will thus be observed that the leather washer Sli of the oil seal is adapted to wipe against-the side of lthe plunger S2 as it moves, and when suitably lubricated will continuously maintain in clean condition that portion of the plunger which enters the guide bore-6 I. All cuttings and foreign niatter are excluded y-frorn the interior or guiding part of the bore E l and there is very4 little wear on the plunger or its guide.

At its upper end the plunger-supporting `member 5i is provided with an'upwardly extending arm 'il having a biiurcated end l2. The parts of the bifurcated end i2 are provided with transverse bores 'Z3 for receiving a cylindrical trunnon 1.4, .which has a transverse bore 'i5-forv slidablyreceiving the rod 16.

The plunger G2 has a flat end portion 11 witha transversely extending bore 13, and the flat end il is adapted to be received in a slot A"r9 located in the handle 8G.

Handle Si) is provided with a small bore 8|, serving as a bearing for the lower end of a screw bolt 32, and with an enlarged bore 83 serving as a bearing for the head of screw bolt 82. Screw bolt 82 is threaded into the bore 1'8 passing through the handle and through the vflat end 11 of the plunger, and pivotally mounts thehandle 8S on the plunger 62.V

At its upper end in Fig. 4 thehandle ll'is provided with a cylindrical-bore 84, as wellfas the cuttings plunger 25 slot 19, previously described, and the rod 16 has an enlarged portion 85 which is xedly secured in the bore 84, such as, for example, by a drive fit. The end 'i5 of the rod is slidably mounted in the trunnion I4, and the trunnion lli is rotatably mounted in the bores 73.

As the handle d is oscillated from left to right, or vice versa, in Fig. d, moving the plunger in a corresponding direction, the rod l5 slides back and forth in the trunnion i4, and the trunnion 'i6 rotates in the bores '13. Trunnion M is r tained against axial movement by the rod 16, which is confined in the slot 85. The lower or left hand end of plunger 62 (Fig. 6) is provided with a bore 3'! and with a transverse communicating threaded bore 38.

The threaded bore 83 is adapted to receive the threaded diamond-supporting screw 89 having a lmurled head SQ and having at its opposite frusto-conical end the cutting diamond 9i. The bore 3l' contains a slidably mounted cylindrical plunger e2 having a ilat end Q3 engaging a helical compression spring' 9e. The opposite end of the spring 9d is seated upon a metal washer plate 95 in the lower end of bore 8'?. The plunger 92 is provided with a beveled end 96 so that its point E37 engages the upper side of the threaded member 8S, and the plunger 92 not only provides sucient friction on the threaded member 8S to retain it in any adjusted position, but the beveled surface 9S is located on that side from which the grinding stone rotates, and the beveled surface @E is adapted to take up all the lost motion between the screw 89 and its bore 83 so that there is no lost motion due to wear of the threaded surfaces.

l The base i3 also supports a horizontally extending table 9S having a threaded bore le@ for receiving the threaded end iti of the dresser pilot 23. Dresser pilot 23 has a cylindrical enlargement iii? above the threaded end and an annular shoulder m3 which engages the top of the table de when the threaded portion it! is threaded home.

The pilot is also provided with the accurately cylindrical portion 2E!! at the top made of hardcned steel for engaging in the hardened steel sleeve 35 which is carried by the tool holder 2| and is rotatably and slidably mounted on the pilot.

. For the purpose of adjustably supporting the grinding stone in predetermined position a metal sleeve i535, the end of which is closed by an inwardly extending flange it, is mounted slidably on the cylindrical portion 62.

A bore it? in the end H16 slidably receives the cylindrical portion ltd of the pilot, and the outer surface of the sleeve 925 is provided with a helical groove ISS, preferably substantially rectangular in section. The table S9 also has another transverse bore litt for receiving the reduced end ill) of a stud il i.

A set screw H2 secures the end Ht! in the bore i553, and the stud Hi has a horizontally extending threaded bore i i3 for receiving the screw bolt Hd, which has a reduced cylindrical end H5. End H5 may be slidably received in the groove Hi8, and the sleeve E95 may be rotated until it reaches any predetermined height within its range of movement, whereupon it may be secured there by turning in the .screw Hd until the end abuts against the sleeve H35.

A suitable steel washer i i6 is preferably used above the end of the sleeve 905, and the tool holder rests upon the washer H6 through the engagement of the lower end of the hardened metal sleeve 3G with Washer H6.

The operation of dressing a grinding stone with the present apparatus may be described as follows: The stone is mounted on the tool holder, and the tool holder is slidably and rotatably mounted on the dresser pilot.

The plunger 62 is set at a predetermined angle by means of the knife-like edge l il of the plunger supporting member 5i and the indicia 60, the plunger-supporting member 5I being clamped in place by turning in the screw bolt 41. i

The sleeve it, which supports the stone at proper height, is then adjusted so that the diamond will just touch the stone. The motor driver is placed with the end 29 of its drive shaft in the non-circular socket 3), and the motor is turned on.

As distinguished from the operation of grinding, the motor should be held as nearly vertical as possible in the dressing operation so that the grinding stone will be rotated upon the true axis of the pilot 23 as nearly as that can be accomplished without vibration. The grinding stone is then dressed by moving the handle 80 back and forth to reciprocate the plunger and cause the dressing diamond to move across the face of the stone, and the stone is accurately dressed to frusto-conical form. The cut which is taken should be as small as possible.

The present dressing apparatus is adapted to be used for long periods of time without losing its accuracy because the plunger and its guide are protected against the cuttings and abrasive material and will not be Worn in such manner as to cause inaccuracy.

The force multiplying handle 86 enables the operator to move the dressing diamond more steadily and uniformly and is more satisfactory from this point of view than a spring actuating plunger, which requires exertion of a greater force and sometimes sticks. The guide surfaces of the plunger and its support being protected, there is little danger in this case of the plunger sticking, and the dressing operation may be carried out in such manner as to provide a very accurate frusta-conical surface on the stone. While I have illustrated a preferred embodiment of my invention, many modications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim is new and desire to secure by Letters Patent of the United States, is:

1. In a valve grinder dressing machine, the combination of a supporting base having an upwardly extending web with a metal plate pivotally mounted on said web, said web having a plurality of indicia, and said plate having a bore, a plunger slidably mounted in said bore, a dressing member mounted on said plunger, said plate having counterbores at each end of said plunger and non-metallic means mounted in said counterbores for maintaining said plunger and bore clean of abrasive material.

2. In a valve grinder dressing machine, the combination of a supporting base having an upwardly extending web with a metal plate pivotally mounted on said web, said web having a plurality of indicia, and said plate having a bore, a plunger slidably mounted in said bore, a dressing member mounted on said plunger, said plate having .counterbores at each end of said plunger and non-metallic means mounted in said counterboresfonmaintaining said plunger and bore clean of abrasive material, said non-metallic means comprising leather members having cylindrical anges engaging said plunger and a helical coil spring on each of said cylindrical flanges for drawing said leather into engagement with said plunger.

3. In a dressing tool, the combination of a supporting base with an upwardly extending portion, a plunger guide pivotally mounted on said upwardly extending portion, said upwardly extending portion having an arcuate slotted threaded member threaded into said plunger guide and extending through said slot and having a shoulder for engaging the opposite side of said upwardly extending portion to draw said plunger guide against said upwardly extending portion and secure the same, said plunger guide having a bore through the same, a plunger slidably mounted in said bore, a lever mounted on said plunger, a trunnion pivotally mounted on said plunger guide, the end of said lever being slidably mounted vin said trunnion.

4. In a dressing tool, the combination of a supporting base with an upwardly extending portion, a plunger guide pivotally mounted on said upwardly extending portion, said upwardly eX- tending portion having an arcuate slotted threaded member threaded into said plunger guide and extending through said slot and having a shoulder for engaging the opposite side of said upwardly extending portion to draw said plunger guide against said upwardly extending portion and secure the same, said plunger guide having a bore through the same, a plunger slidably mounted in said bore, a lever mounted on said plunger, a trunnion pivotally mounted on said plunger guide, the end of'said lever being slidably mounted in said trunnion, said plunger having a transversely extending threaded member carrying a dressing member, and a beveled plunger located in said first-mentioned plunger and engaging said threaded member to urge the threaded member toward the side toward which the grinding stone is rotated to take up any lost motion oi the threaded member in its threaded socket. l

5. In a dressing tool, the combination of a base having an upwardly extending pilot stem carried by said base, a plunger slidably mounted on said base, a hand lever for reciprocating said plunger, a transversely extending threaded membercarried by said plunger and having a dressing member thereon. a tool holder rotatably mounted on said pilot, and a grinding stone carried by said tool holder to be dressed by said dressing `member when said plunger is reciprocated.

6. In a dressing tool, the combination of a base having an upwardly extending pilot stem carried by said base, a plunger slidably mounted on Said base, a hand lever for reciprocating said plunger, a transversely extending threaded member 'carried by said plunger and having va dressing member thereon, a tool holder rotatably mounted on said pilot, and a grinding stone carried by said tool holder to be dressed by said dressing member when said plunger is reciprocated, said tool holder having a hardened steel sleeve engaging said pilot, and said pilot having a 'hardened steel surface to prevent the taking up of abrasive material by either Vof said sleeve or pilot.

7. In a dressing tool, the combination of a base having an upwardly extending pilot stem carried by said'base, a plunger slidably mounted on said base, a hand lever for reciprocating said plunger, a transversely extending threaded member carried by said plunger and having a dressing member thereon, a tool holder rotatably mounted on said pilot, and a grinding stone carried by .said tool holder to be dressed by said dressing member when said plunger is reciprocated, and a driving member comprising an electric motor having a drive shaft with a non-circular end engaging in a non-circular socket in said tool holder, said tool holderv having a resilient metal .member for supporting the end of said shaft.

8. In a dressing tool, the combination of a base having an upwardly extending pilot stem carried by said base, a plunger slidably mounted on said base, a hand lever for reciprocating said plunger, a transversely extending threaded member carried by said plunger and having a dressing member thereon, a tool holder rotatably mounted on said pilot, and a grinding stone carried by said tool holder to be dressed by said dressing .mem-

ber when said plunger is reciprocated, and al vdriving member comprising an electric .motor having a drive shaft with a non-circular end engaging in a non-circular socket in said tool holder, said tool holder having a resilient metal member for supporting the end of said shaft, said drive shaft being slidably mounted in said .motor housing, and resilient means forurging said drive shaft outward and resiliently supporting said motor when the drive shaft is resting on the tool holder.

FRANS O. ALBERTSON. 

